AlwaysScrollableScrollPhysics class Null safety

Scroll physics that always lets the user scroll.

This overrides the default behavior which is to disable scrolling when there is no content to scroll. It does not override the handling of overscrolling.

On Android, overscrolls will be clamped by default and result in an overscroll glow. On iOS, overscrolls will load a spring that will return the scroll view to its normal range when released.

See also:

  • ScrollPhysics, which can be used instead of this class when the default behavior is desired instead.
  • BouncingScrollPhysics, which provides the bouncing overscroll behavior found on iOS.
  • ClampingScrollPhysics, which provides the clamping overscroll behavior found on Android.
Inheritance

Constructors

AlwaysScrollableScrollPhysics({ScrollPhysics? parent})
Creates scroll physics that always lets the user scroll.
const

Properties

allowImplicitScrolling → bool
Whether a viewport is allowed to change its scroll position implicitly in response to a call to RenderObject.showOnScreen.
read-onlyinherited
dragStartDistanceMotionThreshold → double?
The minimum amount of pixel distance drags must move by to start motion the first time or after each time the drag motion stopped.
read-onlyinherited
hashCode → int
The hash code for this object.
read-onlyinherited
maxFlingVelocity → double
Scroll fling velocity magnitudes will be clamped to this value.
read-onlyinherited
minFlingDistance → double
The minimum distance an input pointer drag must have moved to to be considered a scroll fling gesture.
read-onlyinherited
minFlingVelocity → double
The minimum velocity for an input pointer drag to be considered a scroll fling.
read-onlyinherited
parent → ScrollPhysics?
If non-null, determines the default behavior for each method.
finalinherited
runtimeType → Type
A representation of the runtime type of the object.
read-onlyinherited
spring → SpringDescription
The spring to use for ballistic simulations.
read-onlyinherited
tolerance → Tolerance
The tolerance to use for ballistic simulations.
read-onlyinherited

Methods

adjustPositionForNewDimensions({required ScrollMetrics oldPosition, required ScrollMetrics newPosition, required bool isScrolling, required double velocity}) → double
Describes what the scroll position should be given new viewport dimensions.
inherited
applyBoundaryConditions(ScrollMetrics position, double value) → double
Determines the overscroll by applying the boundary conditions.
inherited
applyPhysicsToUserOffset(ScrollMetrics position, double offset) → double
Used by DragScrollActivity and other user-driven activities to convert an offset in logical pixels as provided by the DragUpdateDetails into a delta to apply (subtract from the current position) using ScrollActivityDelegate.setPixels.
inherited
applyTo(ScrollPhysics? ancestor) → AlwaysScrollableScrollPhysics
Combines this ScrollPhysics instance with the given physics.
override
buildParent(ScrollPhysics? ancestor) → ScrollPhysics?
If parent is null then return ancestor, otherwise recursively build a ScrollPhysics that has ancestor as its parent.
protected">@protectedinherited
carriedMomentum(double existingVelocity) → double
Returns the velocity carried on repeated flings.
inherited
createBallisticSimulation(ScrollMetrics position, double velocity) → Simulation?
Returns a simulation for ballistic scrolling starting from the given position with the given velocity.
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed.
inherited
recommendDeferredLoading(double velocity, ScrollMetrics metrics, BuildContext context) → bool
Provides a heuristic to determine if expensive frame-bound tasks should be deferred.
inherited
shouldAcceptUserOffset(ScrollMetrics position) → bool
Whether the scrollable should let the user adjust the scroll offset, for example by dragging.
override
toString() → String
A string representation of this object.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited